• Title, Summary, Keyword: N-containing compound

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Production of O-GlcNAc Modified Recombinant Proteins in Escherichia coli

  • LIM, KI HONG;CHANG HOON HA;HYO IHL CHANG
    • Journal of Microbiology and Biotechnology
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    • v.12 no.2
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    • pp.306-311
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    • 2002
  • O-linked N-acetylglucosamine (O-GlcNAc) is an abundant posttranslationally modified compound in eukaryotic cells. Human O-GlcNAc transferase (OGT) was produced as a maltose binding protein (MBP) fusion protein, which showed significant catalytic activity to modify recombinant Sp1, transcription factor. To facilitate the production of O-GlcNAc modified proteins, instead of using the tedious in vitro glycosylation reaction or expression in eukaryotic cells, a MBP-fusion OGT expression vector (pACYC184-MBPOGT) was constructed using pACYC184 plasmid, which could coexist with general prokaryotic expression vectors containing ColE1 origin. By cotransforming pACYC184-MBPOGT and pGEX-2T vectors into Escherichia coli BL21, intracellular O- GlcNAcylated proteins could be obtained by a simple purification procedure. It is expected that this may be a useful tool for production of O-GlcNAc modified proteins.

Polyhydroxyamic Acid from 3,3′ - Dihydroxybenzidine and Pyromellitic Dianhydride as a Fire-safe Polymer

  • Park, Seung Koo;Farris, Richard J.;Kantor, Simon W.
    • Fibers and Polymers
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    • v.5 no.2
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    • pp.83-88
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    • 2004
  • In order to assess the potential of the hydroxy-containing polyamic acid (PHAA) synthesized from 3,3'-dihydroxy benzidine and pyromellitic dianhydride for a fire-safe polymer, the cyclization pathway of PHAA has been investigated using a model compound prepared from 2-aminophenol and phthalic anhydride. The reaction was monitored. by $^1{H-nuclear}$ magnetic resonance. N-(2-hydroxyphenyl) phthalamic acid is converted to N-(2-hydroxyphenyl) phthalimide at ca. 175$^{\circ}C$, showing endothermic reaction. The imide structure is rearranged to the benzoxazole structure over ca. $400^{\circ}C$. These results are similar with that of PHAA. According to pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) data, water and carbon dioxide are released during the cyclization and rearrangement reaction. One DMAc molecule is complexed with one carboxyl acid group in PHAA, which accelerates the imidization process to release more easily the flame retardant, water.

Synthesis and Characterization of Schiff Base Metal Complexes and Reactivity Studies with Malemide Epoxy Resin

  • Lakshmi, B.;Shivananda, K.N.;Prakash, Gouda Avaji;Isloor, Arun M.;Mahendra, K.N.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.2
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    • pp.473-482
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    • 2012
  • A novel malemide epoxy containing Co(II), Ni(II) and Cu(II) ions have been synthesized by curing malemide epoxy resin (MIEB-13) and Co(II), Ni(II) and Cu(II) complexes of macrocyclic bis-hydrazone Schiff base. The Schiff base was synthesized by reacting 1,4-dicarbnyl phenyl dihydrazide with 2,6-diformyl-4-methyl phenol. The Schiff base and its Co(II), Ni(II) and Cu(II) complexes have been characterized by elemental analyses, spectral (IR, $^1H$ NMR, UV-vis., FAB mass, ESR), thermal and magnetic data. The curing reaction of maleimide epoxy compound with metal complexes was studied as curing agents. The stability of cured samples was studied by thermo-gravimetric analyses and which have excellent chemical (acid/alkali/solvent) and water absorption resistance. Further, the scanning electron microscopy (SEM) and definitional scanning colorimetric (DSC) techniques were confirmed the phase homogeneity of the cured systems.

The 3-[3α(2α-Hydroxy)pinane]-4,5-(pinan)-1,3-oxazolidine Synthesis, Structure and Properties

  • Bialek, Magdalena;Trzesowska, Agata;Kruszynski, Rafal
    • Bulletin of the Korean Chemical Society
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    • v.28 no.1
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    • pp.89-94
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    • 2007
  • The new pinane derivative containing unique multifused ring system was synthesized. The crystal, molecular and electronic structure of the title compound has been determined. Both pinane ring systems have the same conformation. The five-membered oxazolidine ring exists in twisted chair conformation. The structure is expanded through O-H…O hydrogen bond to semiinfinite hydrogen-bonded chain. The bond lengths and angles in the optimised structure are similar to the experimental ones. The CH3 and CH2 groups (except this of oxazolidine ring) are negatively charged whereas the CH groups are positively charged. The largest negative potential is on the oxygen atoms. The C-N natural bond orbitals are polarised towards the nitrogen atom (ca. 61% at N) whereas the C-O bond orbitals are polarised towards the oxygen atom (ca. 67% at O). It is consistent with the charges on the nitrogen and oxygen atom of oxazolidine ring and the direction of the dipole moment vector (3.08 Debye).

Study on Polarographic Reduction of p-Nitrobenzeneazoresorcinol in Dimethylsulfoxide (디메틸술폭시드용매 속에서 파라니트로벤젠아조레조르시놀의 폴라로그래피的 還元에 관한 硏究)

  • Chil Nam Choe;Ki Hyung Jo;Chu Hyun Choe
    • Journal of the Korean Chemical Society
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    • v.30 no.5
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    • pp.433-440
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    • 1986
  • The direct current polarographic behavior of 4n-BAR in dimethylsulfoxide as an aprotic solvent have been investigated. The reduction of 4n-BAR in 0.05M sodium perchlorate solution proceeds along two one-electron steps to give the corresponding compound containing hydrazo groups, each reduction wave was considerably diffusion controlled and irreversible. By addition of acid HAc to 4n-BAR in DMSO solvent, the two reduction waves have coalesced into one in the condition M $\geq$ mole ratio, acid/reductant(M = 2), the slope of $log(i_d-i)(Mi_d/2-i)/i$/ vs. (-E) is irreversible along one-electron steps reduction waves.

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A Synthesis of New Fluorine-containing Phenylformamidines Possessing N-Dialkylaminosulfenyl Group and Their Insecticidal Activities (N-Dialkylaminosulfenyl 치환체를 갖는 새로운 불소 함유 Phenylformamidine 유도체의 합성과 살충활성)

  • Lee, Dong-Guk;Chung, Kun-Hoe;Ko, Young-Kwan;Ryu, Jae-Wook;Woo, Jae-Chun;Koo, Dong-Wan;Choi, Yong-Ho;Park, No-Joong;Kim, Tae-Joon;Choi, In-Young
    • The Korean Journal of Pesticide Science
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    • v.14 no.3
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    • pp.199-208
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    • 2010
  • Phenylformamidine derivatives are well known as insecticides for their specific activity against the insects. It has now been established that they show insecticidal activity as agonists on the octopamine receptor. In order to get a highly active compound we have intensively exploited fluorine substituted-aromatic formamidines possessing N-dialkylaminosulfeny group. Up to now, there are several candidates we found: N-(dialkylamino)sulfenyl-N-methyl-N'-(4-fluoro-2-methylphenyl)formamidines. The miticidal activity of Compound 29 show five-fold higher than Amitraz.

Low Temperature Latent Heat Storage Material of Cooling Characteristics According to Concentration of TMA (TMA 농도에 따른 저온잠열축열물질의 냉각특성)

  • Kim, Chang-Oh;Chung, Hyun-Ho;Chung, Nak-Kyu
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.2
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    • pp.173-178
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    • 2010
  • The ice storage system uses water for low temperature latent heat storage. However, a refrigerator capacity are increased and COP are decreased due to supercooling of water in the course of phase change from liquid to solid. This study investigates the cooling characteristics of the TMA-water clathrate compound including TMA (Tri-methyl-amine, $(CH_3)_3N$) of 20~25 wt% as a low temperature latent heat storage material. The results showed that the phase change temperature are increased and the supercooling degree and the specific heat are decreased according to the weight concentration of TMA increased. Especially, the clathrate compound containing TMA 25wt% has the average phase change temperature of $5.8^{\circ}C$ and the supercooling degree of $8.0^{\circ}C$, retention time of liquid phase for 651sec and specific heat of 3.499 kJ/kgK in the cooling process. This expressed good than different concentration of TMA cooling characteristic. Like this, to apply TMA 25wt%-water clathrate compound is determined by advantageous as the low temperature latent heat storage material.

Antitumor compounds from fruiting bodies of cultivated fungus of Paecilomyces japonica

  • Nama Ryu;Lim, Soon-Sung;Jung, Sang-Hoon;Cho, Sae-Yun;Shin, Kuk-Hyun
    • Proceedings of the Korean Society of Applied Pharmacology
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    • pp.185-185
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    • 1998
  • As part of our continuing attempts to evaluate biologically active compounds from fruiting bodies of cultivated fungus of Paecilomyces japonicus Yasuda, we conducted series of experiments on various fractions and compounds isolated by systematic fractionations. Our main efforts were concentrated on searching for compounds showing antitumor activities, which were tested on mice carrying Sarcoma-180 ascitic tumor. The antitumor activity was assessed by the life spans after these mice were administered Lp. with test compounds for consecutive 20 days. One of two pure compounds, which we have isolated to date, demonstrated significant prolongation of life span. ( Mean Survival Time: 30.3 days compared to that of control: 23.6 days). Structural analysis showed that this compound corresponds to D-mannitol. On the other hand, Ergosterol, another isolated pure compound didn't show efficient antitumor activity. We also obtained water-soluble fractions containing protein-bound polysaccharides and n-butantol fractions, which showed strong antitumor activities, 35.4(150%) and 32.1(136.0%) days of MST, respectively. In SRB assay, however, the test materials didn't show any toxic effects, but the level of acid phosphatase increased significantly when they were applied in cultured macrophage in vitro. Therefore, we concluded that antitumour activities might be attributed to immunostimulating rather than cytotoxic effects. Further experiments are underway to purify and structurally characterize new antitumour compounds from the active fractions.

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Isolation of Dibromosceptrin with Antimalarial Activity from the Unidentified Sponge, Agelas sp. (Agelas속의 미동정 해면으로부터 항말라리아 활성을 갖는 Dibromosceptrin의 분리)

  • Park, Yeung-Beom;Lee, Jong-Soo;Lim, Chi-Won
    • Korean Journal of Pharmacognosy
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    • v.35 no.3
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    • pp.189-193
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    • 2004
  • In order to find some lead compounds for the treatment of opportunistic infections of malaria and pathogenic microbes, an undescribed Indonesian sponge Agelas sp. collected at Manado, Indonesian Waters, was suggested containing active compounds. Crude ethanolic extract of the sponge exhibited significant in vitro antimalarial and antimicrobial activity against Plasmodium falciparum (D6 colne) with $IC_{5O}$ values of $8\;{\mu}/ml$ and against pathogenic microbes such as Candida albicans $(150\;{\mu}/ml)$, Cryptococcus neoformans $(<20\;{\mu}/ml)$, Staphylococcus aureus $25\;{\mu}/ml$, methicillin-resistant Staphylococcus aureus $(<20\;{\mu}/ml)$, and Pseudomonas aeruginosa $(<20\;{\mu}/ml)$. Active compound (5.0 mg) was isolated from the ethanolic extracts of the sponge and purified by using silica gel and ODS column, successively. Active compound was elucidated as dibromosceptrin $(C_{22}H_{24}Br_2N_{10}O_2)$ by detailed analysis of FTESI-MS and comparison of $^1H,\;^{13}C$, DEPT and HMQC NMR spectral data with those reported.

Self-assembly Coordination Compounds of Cu(II), Zn(II) and Ag(I) with btp Ligands (btp = 2,6-bis(N'-1,2,4-triazolyl)pyridine):Counteranion Effects

  • Kim, Cheal;Kim, Sung-Jin;Kim, Young-Mee
    • Korean Journal of Crystallography
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    • v.16 no.2
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    • pp.107-127
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    • 2005
  • Five Cu(II) compounds were obtained from different copper salts with btp ligands, and their structures were determined by X-ray crystallography. The structure of coordination polymer 2 contains btp-bridged tetranuclear Cu(II) units weakly connected by nitrate ions, and the structure of a discrete Cu(II) molecule 1 contains acetates and btp ligands. With perchlorate anions, two btp ligands bridge Cu(II) ions to form a double zigzag chain 3, while a single zigzag chain 4 is created with sulfate anions. The reaction of $Cu(NO_{3})_{2}$ containing $NH_{4}PF_{6}$ with btp ligands also produced a polymeric compound 5 containing $Cu(H_{2}O)_{2}^{2+}$ and $Cu(NO_{3})_{2}$ units alternatively bridged by btp ligands with H-bonds between copper bonded water and nitrate oxygen atoms. Five Zn(II) compounds were obtained from different zinc salts with btp ligands, and the structures of polymeric compounds (6, 7 and 8) and monomeric compounds (9 and 10) were determined by X-ray crystallography. With nitrate, chloride and bromide anions, btp ligands bridge Zn(II) ions to form polymeric compounds (6, 7 and 8), but btp ligands coordinate to a Zn(II) ion to form monomeric complexes (9 and 10) with $PF_{6}^{-}$ and perchlorate anions. Four silver salts and btp ligands produced two kinds of structures, dinuclear 20-membered rings and one-dimensional zigzag chain depending on different anions. For $ClO_{4}^{-}$ and OTf anions, weak interactions between Ag(I) and anions make dinuclear 20-membered rings construct polymeric compounds (11 and 13). For $PF_{6}^{-}$ anion, there are also weak interactions between Ag(I) and $F(PF_{6}^{-})(12)$, but they do not construct a polymeric compound. For $O_{2}CCF_{3}^{-}$ anion, btp ligands bridge Ag(I) atoms to make one-dimensional zigzag chain (14), and there are also interactions between Ag(I) and anions.